§1.1 Field of the Invention
The present invention generally concerns the design of a handheld air plasma spray for sterilization and blood coagulation applications.
§1.2 Background
A torch module described in the article S. P. Kuo, et al., “Design and electrical characteristics of a modular plasma torch,” IEEE Trans. Plasma Sci., Vol. 27, no. 3, pp. 752-758, 1999; and U.S. Pat. No. 6,329,628 titled “Methods and Apparatus for Generating a Plasma Torch,” (“the '628 patent”) can be run in low frequency (e.g., 60 Hz) periodic mode to produce low temperature non-equilibrium air plasma. Based on the principle of this torch module, a portable torch device is devised for applications requiring plasma to be exposed directly to the open air. One of the applications is for sterilizing contaminated objects and the other one is for coagulating blood.
The advantage of producing non-equilibrium plasma is to have a better usage of the electron plasma energy, gained from the discharge, for the production of reactive oxygen species (ROS), rather than for heating the torch. ROS (particularly, the reactive atomic oxygen (RAO)) are effective to kill microorganisms including the toughest biological agents, bacterial spores, such as Anthrax (See, e.g., the articles: H. W. Herrmann et al., “Decontamination of chemical and biological warfare (CBW) agents using an atmospheric pressure plasma jet (APPJ),” Phys. Plasma, Vol. 6, pp. 2284-2289, 1999 (hereafter referred to as “the Herrmann article”); and Wilson Lai et al., “Decontamination of Biological Warfare Agents by a Microwave Plasma Torch”, Phys. Plasmas, Vol. 12, 023501 (1-6), February 2005 (hereafter referred to as “the Lai article”)). The mechanism of killing spores by ROS was explored by scanning electron microscope (SEM) and by atomic force microscope (AFM). The results show that ROS cause changes in spores' morphological structures and shape and thus lead to the destruction of the spores (See, e.g., the article: Olga Tarasenko et al., “Scanning Electron and Atomic Force Microscopy to Study Plasma Torch Effects on B. cereus Spores”, IEEE Trans. Plasma Sci., Vol. 34, No. 4, pp. 1281-1289, August 2006 (hereafter referred to as “the Tarasenko article”)).